HERMES: Towards an Integrated Toolbox to Characterize Functional and Effective Brain Connectivity

The analysis of the interdependence between time series has become an important field of research in the last years, mainly as a result of advances in the characterization of dynamical systems from the signals they produce, the introduction of concepts such as generalized and phase synchronization and the application of information theory to time series analysis. In neurophysiology, different analytical tools stemming from these concepts have added to the ‘traditional’ set of linear methods, which includes the cross-correlation and the coherency function in the time and frequency domain, respectively, or more elaborated tools such as Granger Causality. This increase in the number of approaches to tackle the existence of functional (FC) or effective connectivity (EC) between two (or among many) neural networks, along with the mathematical complexity of the corresponding time series analysis tools, makes it desirable to arrange them into a unified-easy-to-use software package. The goal is to allow neuroscientists, neurophysiologists and researchers from related fields to easily access and make use of these analysis methods from a single integrated toolbox. Here we present HERMES (http://hermes.ctb.upm.es), a toolbox for the Matlab® environment (The Mathworks, Inc), which is designed to study functional and effective brain connectivity from neurophysiological data such as multivariate EEG and/or MEG records. It includes also visualization tools and statistical methods to address the problem of multiple comparisons. We believe that this toolbox will be very helpful to all the researchers working in the emerging field of brain connectivity analysis.     

Low-level laser therapy in different stages of rheumatoid arthritis: a histological study

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease of unknown etiology. Treatment of RA is very complex, and in the past years, some studies have investigated the use of low-level laser therapy (LLLT) in treatment of RA. However, it remains unknown if LLLT can modulate early and late stages of RA. With this perspective in mind, we evaluated histological aspects of LLLT effects in different RA progression stages in the knee. It was performed a collagen-induced RA model, and 20 male Wistar rats were divided into 4 experimental groups: a non-injured and non-treated control group, a RA non-treated group, a group treated with LLLT (780 nm, 22 mW, 0.10 W/cm², spot area of 0.214 cm², 7.7 J/cm², 75 s, 1.65 J per point, continuous mode) from 12th hour after collagen-induced RA, and a group treated with LLLT from 7th day after RA induction with same LLLT parameters. LLLT treatments were performed once per day. All animals were sacrificed at the 14th day from RA induction and articular tissue was collected in order to perform histological analyses related to inflammatory process. We observed that LLLT both at early and late RA progression stages significantly improved mononuclear inflammatory cells, exudate protein, medullary hemorrhage, hyperemia, necrosis, distribution of fibrocartilage, and chondroblasts and osteoblasts compared to RA group (p?<?0.05). We can conclude that LLLT is able to modulate inflammatory response both in early as well as in late progression stages of RA.     

Crystalloid flush with backward unclamping may decrease post‐reperfusion cardiac arrest and improve short‐term graft function when compared to portal blood flush with forward unclamping during liver transplantation

During liver transplant (LT), the release of vasoactive substances into the systemic circulation is associated with severe hemodynamic instability that is injurious to the recipient and/or the post‐ischemic graft. Crystalloid flush with backward unclamping (CB) and portal blood flush with forward unclamping (PF) are two reperfusion methods to reduce reperfusion‐related cardiovascular perturbations in our center. The primary aim of this study was to compare these two methods. After institutional review board (IRB) approval, cadaveric whole LT cases performed between 2003 and 2008 were reviewed. Patients were divided into two groups based on reperfusion methods: CB or PF. After background matching with propensity score, the effect of each method on post‐operative graft function was assessed in detail. In our cohort of 478 patients, CB was used in 313 grafts and PF in 165. Thirty‐day graft survival was lower, and risk of retransplantation was higher in PF. Multivariable model showed that CB is an independent factor to reduce primary non‐function, cardiac arrest and improve 30‐d graft survival. Also, the incidence of ischemic‐type biliary lesions was significantly higher in the PF group. Reperfusion methods affect intraoperative hemodynamics and post‐transplant outcome. CB allows for control over temperature and composition of the perfusate, perfusion pressure, and the rate of infusion.     

Transplantation with hyper-reduced liver grafts in children under 10 kg of weight

Background

We had previously described a left lateral segment hyper-reduction technique capable of sizing the graft according to the volume of the abdominal cavity of the recipient.

Aim

The purpose of our study was to evaluate our 14-year live-donor liver transplantation experience with in situ graft hyper-reduction in children under 10 kg of weight.

Patients and methods

Between January 1997 and May 2011, we performed 881 liver transplants. Two hundred and seventy-seven (n?=?277) involved pediatric recipients, of which 102 (37 %) were from live donors. Thirty-five (n?=?35) patients under 10 kg of weight underwent hyper-reduced living donor liver transplants. There were 21 females (60 %) and 14 males (40 %), with a median age of 12 months (range 3–23) and a median weight of 7.7 kg (range 5.6–10).

Results

Median operative time was 350 min (range 180–510). Median cold ischemia time was 180 min (range 60–300). Twenty-six (n?=?26) patients required intraoperative transfusion of blood products. There were 49 postoperative complications involving 26 patients (74 % morbidity rate). One-, 3-, and 5-year survival rates were 87, 79, and 74 %, respectively. Twenty-eight patients are currently alive.

Conclusions

Hyper-reduced grafts provide an alternative approach for low-weight pediatric recipients. The relatively high immediate postoperative morbidity could be related to the complexity of these patients.     

Gangliosides, Ab1 and Ab2 antibodies II. Light versus heavy chain: An idiotype-anti-idiotype case study

The antibody heavy chain is generally more important than the light chain for the interaction with the antigen, although many reports demonstrate the influence of the light chain in the antibody binding properties. The heavy chains of anti-N-glycolyl-ganglioside P3 mAb and anti-idiotypic 1E10 mAb display complementary charged residues in their H-CDRs, particularly in H-CDR3. A basic residue in P3 mAb H-CDR1 was shown to be crucial for the interaction with the antigen and 1E10 mAb. The immunogenetic features of three other P3 mAb anti-idiotypic mAbs are now analyzed. One of them bears the same heavy chain as 1E10 mAb and a different light chain, but differs in its binding to P3 mAb mutants where H-CDR basic residues were replaced and in the binding to 1E10-specific phagotopes. Chimeric hybrid antibodies with P3 and 1E10 mAb heavy chains and unrelated light chains were obtained to further determine the importance of heavy chains in P3 and 1E10 mAb binding properties. One of the P3 heavy chain hybrid antibodies retained the specificity of P3 mAb with slight affinity differences. The heavy chains appear to play the main role in these mAb interactions, with the light chains modulating the affinity to their ligands.